Proper feed management will maintain the good water quality in the cultured ponds leading to a successful yield. However, good food management is not the only factor required to insure that the shrimp grow well. If the amount of dissolved oxygen (DO) in the pond is too low, the shrimp will eat less and there will be more left over food. This will affect other parameters of water quality, and if the water quality drops the shrimp will get weak and more susceptible to bacterial infection. Such conditions lead to low survival rates. When the DO of the water is low, the shrimp’s growth rate is slow and the feed conversion ratio (FCR) is very high. It takes longer to raise a batch of shrimp than when the DO is sufficient.
Oxygen is the main limiting factor in both recirculating and traditional aquaculture systems. Less than the required levels lead to poor water quality, poor feed conversion ratios (FCR), reduced growth and increased mortality. With high energy prices, energy efficiency is becoming much more important when comparing aeration techniques and devices.
On the intensive shrimp farms in Thailand, most farmers install at least 36 hp of aerators per hectare to be sure that there will be enough water current to keep the bottom of the pond clean in the feeding areas. The sediment is all swept towards the center of the pond. Naturally, the aerators also help raise the amount of dissolved oxygen in the water so that organic material will be decomposed by microorganisms more efficiently. The DO should not drop below 4 ppm, even in the pre-dawn hours. If they wish to produce large biomass of shrimp, most farms use even more aerators, based on the general rule that you can produce about 450 kg of shrimp for every 1 hp of electric motor aerator